The present invention relates in general to apparatus and method for the prevention of sudden infant death syndrome and in particular to an infant safety pad or mattress and corresponding method for the prevention of infant asphyxiation from carbon dioxide poisoning.
Several thousand apparently healthy infants (children under the age of 1 year) die each year in the United States from Sudden Infant Death Syndrome (SIDS). Deaths from SIDS have been estimated at 7,000 to 10,000 per year. See for example Womens Day, volume 55, issue 3, Jan. 7, 1992, pages 38 through 43; and USA Today, volume 117, issue 2626, February 1989, page 11. The occurrence of SIDS in a given family can be particularly devastating emotionally because, in general, there is no warning that the infant is at risk and the parent or care giver has no knowledge of any problem until he or she discovers an unconscious or deceased infant thought to be safely sleeping in its crib.
The specific cause of SIDS is generally unknown, which unfortunately leads to the result that heretofore there has generally been no known treatment and generally no means of prevention.
While no specific cause or causes of the medical disaster are known, the medical community has produced several different theories. One such theory is that the victim infant suffers from some form of neurological disorder (cause unknown and existence undetected). The disorder operates to interrupt the infant's breathing (sometimes referred to as the infant simply "forgetting" to breathe) and death results due to suffocation.
Another theory also suspects infant suffocation, but not due to any neurological disorder interrupting breathing. Instead, it is believed that the infant becomes fatally poisoned by exhaled carbon dioxide which has become trapped or accumulated and then rebreathed by the infant. The theoretical possibility of SIDS death caused by the rebreathing of expired gases, oxygen deficient air, and/or by blocked air passages in bedding has been discussed in the medical and other literature. See for example The Lancet, volume 337, issue 7852, May 25, 1991, pages 1244 through 1257; The Journal of the American Medical Association, volume 263, issue 21, Jun. 6, 1990, pages 2865 through 2869; The New England Journal of Medicine, volume 324, issue 26, Jun. 27, 1991, pages 1858 through 1864; and Time, volume 138, issue 1, Jul. 8, 1991, page 48.
The reason that carbon dioxide poisoning from rebreathing of exhaled gases is suspected is because heretofore the conventional wisdom (i.e., the prevailing advice) has been for small infants to be placed on their stomachs (i.e., a prone position) for best rest and sleep. The reason for this is well known to any parent or care giver; a young infant will frequently regurgitate (i.e., spit up) previously ingested fluids and sometimes become choked by reswallowing the matter. This is a very natural and relatively frequent occurrence, and entirely different from vomiting due to any illness, because the digestive system of the infant at birth and for a time period thereafter is generally inadequately developed so as to consistently retain fluids. Such regurgitation often accompanies burping or hiccups.
If an infant were to be placed on its back (i.e., a supine position) so as to keep its face open and unblocked for safe breathing, there is a recognized and significant risk of aspiration from simple regurgitation of fluids. Aspiration (i.e., taking foreign matter into the lungs during breathing) can result in fatal choking. Matter regurgitated by an infant in a supine position would frequently be retained by gravity in the infant's mouth and potentially reswallowed (aspirated) during breathing. Therefore, to prevent this possibility, infants have been traditionally placed prone or face down for rest or sleep.
The size and weight of a newborn infant's head is relatively large in relation to the remaining body of the infant, and particularly in relation to the initial strength of the infant. Oftentimes a newborn infant is not even able to raise its head adequately so as to turn from one check to another, or to simply raise its face from against the bedding which it rests. Adequate strength for such movements develops relatively quickly, but still may take several weeks or more. Even so, an infant can tire quickly from simply trying to raise its head. At such resting times, and from other movements, an infant may place its own face straight down onto a crib mattress and into the bedding materials, despite any resulting blockage of air passages.
All of the foregoing leads to the situation that even newborn infants are typically placed (at least initially) in a relative prone position (with their head typically turned to one side) for rest or sleep.
A typical conventional crib mattress for supporting an infant takes the form of some resilient or softened pad either relatively impermeable to air, or more often covered with a solid vinyl or plastic permanent covering so as to give form and shape to the mattress and particularly so as to prevent the mattress inner portion from becoming wet from infant regurgitation or other discharges. In other words, a vinyl mattress cover is readily cleaned if there is any spit up or diaper leakage from the infant.
At the same time, due to its relatively uncomfortable vinyl cover, the conventional crib mattress is often further covered with a cloth pad, sheet, baby quilt, or the like, all of which may be relatively loose fitting. In addition, a light blanket or similar object may be used to cover a portion of the infant for warmth. Still further, an infant or young child may have a cloth diaper or similar small blanket which it clutches or grasps in its hands and draws close to it, sometimes close to its face as it snuggles against such blanket or even against the mattress on which it rests.
The foregoing arrangement can result in a combination of materials from which a fragile but not unhealthy baby may be unable to become untangled (if entanglement occurs). As the accident events progress and an infant begins to rebreath the carbon dioxide which it exhales, it becomes weaker to the point of collapsing face down into the bedding mattress. It then continues to rebreath the exhaled carbon dioxide to the point of becoming unconscious, and the infant medically deteriorates from that point to the point of death.
The likelihood of carbon dioxide poisoning as a cause or major factor in SIDS has been regarded as so great and the certain results therefrom are so catastrophic that some pediatricians have recently begun recommending for the first time that infants be placed on their backs for sleeping (i.e., in a supine position). In other words, the previously recognized risk of aspiration from regurgitation by an infant sleeping on its back is believed by some as outweighed by the risk of asphyxiation from carbon dioxide poisoning by an infant sleeping in a prone position.
In the medical care field, it has heretofore been practiced to provide known sick or at risk patients "oxygen therapy." Where a patient has a particular respiratory condition or other demanding condition, pure oxygen or air with an enriched percentage of oxygen may be given to patients such as through either a mask applied to the patient's face or through a tent enclosing the head or upper body portion of the patient. Neonatal anesthesia masks exist but have not generally been used for an infant or small child who was not undergoing some specific therapy or which was not under some specific medical care.
Air circulation in a specific sense has heretofore been practiced in conjunction with certain mattress technology for the intended purpose of preventing and/or treating decubitus ulcers. Ulcerated areas of the skin or bed sores can occur from prolonged or excessive pressure to a specific body point during bed rest, and/or from trapped heat and perspiration. These conditions can be treated and/or prevented by the circulation of air in the vicinity of affected areas. Potentially affected areas typically include bony prominences, for example, such as at the patient's hips, knees, and ankle joints.
Bedford (U.S. Pat. No. 4,686,724) discloses air channels 19 through an open cell foam pad for the intended purpose of preventing decubitus ulcers. Plugs 21 and 22 may be removed from channels 19 in certain areas of the pad body for the creation of air channels in the corresponding area. Williams et al. (U.S. Pat. No. 4,620,337) discloses (column 1, lines 40 through 51) the use of inflatable cells which are alternately inflated and deflated (called alternating pressure pads) for preventing the formation of decubitus ulcers. In column 5, lines 10 through 15, the patent also refers to the use of rib design in the mattress for promoting air circulation between the pad and the patient to disperse body heat and reduce moisture build-up, both related to the formation of decubitus ulcers, and for promoting increased air flow through open cells of the foam pad. Baskent (U.S. Pat. No. 4,768,251) discloses in column 3, lines 4 through 55, the idea of using alternating peaks and valleys to form convolutions which allow air to pass around the peaks thereof through such valleys, again for the purpose of preventing the formation of decubitus ulcers.